摘要
库岸古滑坡复活是水库蓄水运行面临的一个十分突出的地质灾害问题。为研究库岸古滑坡的变形特征与失稳机制,以具有典型多期次滑动特征的藕塘滑坡为对象,概化制作了大型物理试验模型,分别模拟库水涨落和降雨工况,以及两者联合作用的工况,通过试验获得了坡体位移、孔隙水压力和土压力全时程曲线以及滑坡演化数字影像资料。试验结果及分析研究表明:组成滑坡的3个次级滑坡在库水涨落和降雨作用下呈现出不同的变形特征,库水涨落引起的变形主要集中在第一期次滑坡,水位快速上涨对第一期次滑坡体稳定性影响不明显,但水位骤降会诱发第一期次滑坡坡脚局部牵引式崩滑;强降雨会引起第一期次滑坡坡脚垮塌,第二、三期次滑坡体受强降雨作用稳定性下降明显;水位快速下降和强降雨叠加条件下,坡体失稳模式为第一期次滑坡坡脚局部崩滑和/或第三期次滑坡滑移。本模型试验测试数据与滑坡现场监测数据对比分析反映相吻合的坡体变形特征和失稳滑坡趋势,本试验研究所揭示的库岸古滑坡在库水涨落和降雨条件下的变形特征及失稳机制对开展类似滑坡研究和防治提供了参考依据。
The revival of ancient bank landslide is a serious geological hazard in reservoir operation.In order to study the deformation characteristics and instability mechanism of ancient bank landslide,a large-scale physical test model was designed based on Outang landslide which is a typical multi-phase ancient bank landslide.By simulating the fluctuation of reservoir water,rainfall and their combination,the curves of pore water pressure and earth pressure with time and digital image data of landslide evolution were obtained.Results indicate that the three-phase sliding masses that compose the landslides have different deformation characteristics under the reservoir water level fluctuation and rainfall.The deformation due to the fluctuation of reservoir water is mainly concentrated in the first phase sliding mass.The rapid rise of the water level has no obvious effect on the first phase sliding mass.But the rapid decrease of water level induces a local retrogressive sliding at the toe of first phase sliding mass.Heavy rainfall causes a local retrogressive sliding at the toe of the first phase sliding mass,and the stability of the second and third phase landslides decrease obviously.The failure mode under the rapid decline of water level and heavy rainfall is local retrogressive sliding at the toe of the first phase sliding mass or/and sliding of the third phase sliding mass.The experimental phenomena coincide with the deformation characteristics and the developing tendency of actual reservoir landslide.This study provides the deformation characteristics and instability mechanism of the ancient landslide in reservoir bank under the condition of reservoir water level fluctuation and rainfall,which is helpful for the research and prevention of similar landslides.
作者
肖捷夫
李云安
胡勇
张申
蔡浚明
XIAO Jie-fu;LI Yun-an;HU Yong;ZHANG Shen;CAI Jun-ming(Faculty of Engineering,China University of Geosciences,Wuhan,Hubei 430074,China;Department of Civil Engineering,Wenhua College,Wuhan,Hubei 430074,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2021年第2期471-480,共10页
Rock and Soil Mechanics
基金
科技部重点研发计划项目(No.2018YFC0809402)
国家重点研发计划项目(No.2017YFC1501301)
国家重点基础研究发展计划(973)项目(No.2011CB710602)
关键词
库岸古滑坡
物理模型试验
库水涨落
降雨
变形演化
ancient bank landslide
physical model test
water level fluctuation
rainfall
deformation evolution
作者简介
第一作者:肖捷夫,男,1990年生,博士研究生,主要从事岩土体力学特性及失稳机制研究。E-mail:734361304@qq.com;通讯作者:李云安,男,1965年生,博士,教授,主要从事岩土工程方面的教学与科研工作。E-mail:liyunan@cug.edu.cn
